home/bin/wallpapers_preview

   1 #! /bin/bash
   2
   3 ### XXX Chose not to 'set -e' because arithmetic evaluation can cause a non-zero exit.
   4 ### XXX Chose not to 'set -u' because unset params ($1, $2, ...) cause failures.
   5 ### Solutions to the above are ugly.
   6
   7 declare -a paths
   8 declare -i n=0
   9
  10 read_command() {
  11     local char
  12
  13     read -rsn 1 char
  14     case "$char" in
  15         q | Q) echo 'CMD_QUIT';;
  16         h | H) echo 'CMD_MOVE_BACK';;
  17         l | L) echo 'CMD_MOVE_FORWARD';;
  18         f | F) echo 'CMD_FAVORITE';;
  19             *) echo 'CMD_UKNOWN';;
  20     esac
  21 }
  22
  23 paths_set() {
  24     local path
  25
  26     while read -r path
  27     do
  28         if file "$path" | grep 'image data' > /dev/null
  29         then
  30             (( n++ ))
  31             # \r jumps to the beginning of the line:
  32             printf '\rFound %d images.' "$n" >&2
  33             paths["$(( n - 1 ))"]="$path"
  34         fi
  35     done
  36     printf '\n' >&2
  37 }
  38
  39 paths_set_from_dir_find() {
  40     paths_set < <(find "$1" -type f)
  41 }
  42
  43 paths_set_from_favs() {
  44     paths_set < <(sort -k 2 "$FILE_WALLPAPER_FAVS" | awk '{sub("^" $1 " +", ""); print}')
  45 }
  46
  47 set_wallpaper() {
  48     local -ri i="$1"
  49     local -r path="$2"
  50
  51     printf '%d of %d %s\n' "$(( i + 1 ))" "$n" "$path"
  52     feh --bg-scale "$path"
  53 }
  54
  55 paths_preview() {
  56     local -i i=0
  57     local path="${paths[$i]}"
  58
  59     set_wallpaper "$i" "$path"
  60
  61     while :
  62     do
  63         if [[ "${paths[$i]}" != "$path" ]]
  64         then
  65             path="${paths[$i]}"
  66             set_wallpaper "$i" "$path"
  67         fi
  68
  69         case "$(read_command)" in
  70             CMD_QUIT)
  71                 exit 0;;
  72             CMD_MOVE_BACK)
  73                 (( i = i == 0 ? (n - 1) : i - 1));;
  74             CMD_MOVE_FORWARD)
  75                 (( i = (i + 1) % n ));;
  76             CMD_FAVORITE)
  77                 wallpaper_fav;;
  78             CMD_UKNOWN)
  79                 continue;;
  80         esac
  81     done
  82 }
  83
  84 main() {
  85     case "$1" in
  86         f | fav) paths_set_from_favs;;
  87         d | dir) paths_set_from_dir_find "$2";;
  88         a | all) paths_set_from_dir_find "$DIR_WALLPAPERS";;
  89         '')
  90             paths_set_from_dir_find "$DIR_WALLPAPERS";;
  91         *)
  92             printf 'Error: unknown source "%s"\n' "$1" >&2
  93             exit 1;;
  94     esac
  95
  96     paths_preview
  97 }
  98
  99 main "$@"